Tributoxysiloxychlorosilanes [(BuO)3SiO]xSiCl4−x(Bu=t: x=1,2; Bu=s: x=1,2,3 or 4) were prepared by the reaction of silicon tetrachloride with tributoxysilanol in the presence of pyridine. The hydrolysis of these compounds led to the formation of tributoxysiloxysilanols [(BuO)3SiO]xSi(OH)4−x (Bu=t: x=2; Bu=s: x=2 or 3). Tri-t-butoxysiloxysilanetriol was obtained from the corresponding trichlorosilane under mild hydrolytic conditions by using aniline as an hydrogen-chloride acceptor. On the other hand, the hydrolysis of the trichlorosilane with excess water in the presence of pyridine gave a resinous product. The fractional precipitation of this product gave a white powder soluble in such organic solvents as benzene, n-hexane, ether, and carbon tetrachloride; the powder had a molecular weight between 2500 and 4300. This resin turned into glassy solids upon being heated at 200 or 300°C under reduced pressure; these solids had molecular weights between 5500 and 12500. The possible structures for these polymeric substances were discussed on the basis of the results of the elemental analysis, the IR spectra, and the gas chromatography of volatile substances produced in the course of polymerization.
In the reacion of aryl bromide with carbon monoxide in the presence of water and a catalytic amount of nickel carbonyl, it has been found that aromatic carboxylic acids (benzoic acid, polymethylbenzoic acid, α-naphthoic acid, etc.) are formed in very high yields when such salts of carboxylic acids as potassium acetate or sodium benzoate are added to the starting materials. The carbonylation reaction of aryl bromide is strongly inhibited by the hydrobromic acid formed, and the addition of the salt of carboxylic acid effectively decreases its concentration in the course of the reaction. When the amount of potassium acetate is larger than that of aryl bromide, the rate of the carbonylation reaction of bromobenzene to form benzoic acid is proportional to the amounts of bromo-benzene, nickel tetracarbonyl, and water and to the reciprocal of the carbon monoxide pressure. From these kinetic data, the effect of the salts of carboxylic acids and the course of the reaction are discussed.
A polyester containing 2,5-diamino-p-benzoquinone nuclei was prepared by the polycondensation of 2,5-bis(ω-carboxyl-pentylamino)-p-benzoquinone with polyethylene glycol 400 at 160°C, 170°C and 180°C. At 160°C the esterification was brought about easily without gelation, giving an amino-quinoid polyester (prepolymer), but above 170°C an unexpected gelation was observed. The amino-quinone nuclei incorporated in the polyester thus prepared were confirmed by NMR spectroscopy. To make clear the influence of the amino-quinone nuclei upon the gelation, the thermal reactions of the model compounds, the above amino-quinoid dibasic acid, and its ethyl ester were investigated by means of IR spectroscopy and chemical analysis. It was concluded that the hydrogen atoms in the amino-groups of the quinone move to the oxygen atoms and that the resulting hydroxy groups combine with each other to form an ether bond as a result of dehydration. When the prepolymer prepared at 160°C was heated at 170°C for 4 hr with p-toluenesulfonic acid (5% by weight) or at 180°C for 8 hr without the acid catalyst, there was obtained an infusible and insoluble film which made crosslinkage as shown in the above mechanism.
The properties of acid-acetate baths containing hypophosphite as a reducing agent were studied in an attempt to obtain an electroless nickel deposit; further, the protective property of such deposits with phosphorus contents of 4 to 13% was investigated. The hypophosphite utilization efficiency for the deposition of electroless nickel was found to be 0.33; the deposition rate indicates a first-order dependence on hypophosphite, but it is independent of nickel concentration, within the limits specified in the range of suitable conditions. The phosphorus content of the deposits increases with a decrease in the pH value of the bath and with an increase in the initial concentration of hypophosphite, but it is independent of that of nickel. An electoless nickel with a high phosphorus content affords more protection against metallic bases.